SAF E TY | Sponsored editorial
INDUSTRIAL REVERSE OSMOSIS
Reverse osmosis (RO) is widely applied to remove salts and other substances from process water. Bacterial growth on RO membranes can greatly reduce the efficiency of this process, so large amounts of chemicals (known as biocides) are dosed in the water, to prevent the proliferation of bacteria. Many biocides are oxidizers, and contact with RO membranes should be avoided.
F
or this reason, a tradeoff has to be achieved between the efficiency of chemical treatment and the prevention of damages caused by such substances. In the Figure 1 example, this power plant used reverse osmosis to produce demineralized water for cooling of heat exchangers. Raw water was treated with a biocide, then passed ultrafiltration and was stored in a tank. RO was then applied. One ALVIM Sensor was installed before RO, in the feedwater line, and another one in the concentrate line. The signal from the two ALVIM Sensors was acquired by the data acquisition system of the plant, along with the other data from the process. Laboratory analyses (CFU count)
were periodically carried out on water samples taken from different points. While this kind of analysis provides a rough indication of the number of free-floating (planktonic) bacteria in the water, the ALVIM Sensor monitors the growth of biofilm. After the settlement of the first bacteria coming from water bulk, biofilm growth is no longer related to the presence of free-floating
bacteria. The microorganisms settle on surfaces, duplicate themselves, growing independently from the planktonic ones. More than 90 per cent of bacteria live in biofilms, and these structures provide better protection from external agents, including biocides and other chemicals. This makes biofilm up to 1000x more resistant to sanitation than free-floating bacteria.
FIGURE 1
NEW
TURBIDITY MONITOR
PULSAR
MICROFLOW
Sample Biofilm growth signal over time
ALVIM
BIOFILM ANALYSER Continuous Biofilm Monitoring • Early detection of Bacterial Growth on surfaces • Monitoring & optimisation of sanitation requirements.
Open Channel Flow & Velocity measurement
PROCESS INSTRUMENTS
• • • • • •
• Residual Chlorine • Dissolved Ozone • Dissolved Oxygen • Suspended Solids
ANALYTICAL CONTROLLERS
Lightweight, compact design No interruption to service ATEX Ex mb Zones 1 & 2 approval Minimal installation costs • Maintenance-free RS485 Modbus • IP68 Non-contacting • Cost-effective
• PH/ORP • Conductivity • Fluoride • Turbidity
Many other measurements available
PULSAR
LEVEL METERS • Ultrasonic Transmitters and Controllers • Point Level Switches • Sludge Level Systems • Wireless Systems
BINTECH SYSTEMS WATER SOLUTIONS 1300 363 163 68
UTILITY • NOVEMBER 2021
sales@bintech.com.au www.bintech.com.au
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